Driver for rotary tools



May 7, 1963 N. DUCHESNE DRIVER FOR ROTARY TOOLS 2 Sheets-Sheet 1 Filed Aug. 15, 1960 /2 1/ m a M INVENTORY Normand Dual BY ESNE PATENT AGENT y 7, 1963 N. DUCHESNE 3,088,338

DRIVER FOR ROTARY TOOLS Filed Aug. 15, 1960 2 Sheets-Sheet 2 IN VE N TOE Normand DUCfi/ESWE BYQILIUv-EW BQTENT AGENT 3,088,338 DRIVER FOR ROTARY TGOLS Normand Duchesne, 332 Tessier St., La Tuque, Quebec, Canada Filed Aug. 15, 1960, Ser. No. 49,754 2 Claims. (Cl. 74-757) The present invention relates to rotary tools such as screw driver, socket wrench and the like, and more particularly to manually operated driving means for such tools.

The main object of the present invention resides in the provision of a handle for rotary tools which incorporates gearing to vary the speed of rotation of the tool itself with respect to the handle.

Yet another important object of the present invention resides in the provision of a driving handle of the character described in which the tool may he attached to either end of the handle for either increasing or decreasing the speed of rotation of the tool with respect to the handle.

Yet another object of the present invention resides in the provision of a handle of the character described in which the gears are arranged in a symmetrical manner and the transmission torque is equally balanced resulting in smooth operation of the tool with a minimum of friction in the gearing assembly.

Yet another important object of the present invention resides in the driving handle of the character described which is of relatively simple, inexpensive and yet very sturdy construction.

The foregoing and other important objects of the present invention will become more apparent during the following disclosure and by referring to the drawings, in which:

FIGURE 1 is a longitudinal section of a first embodiment, some of the parts being shown in elevation;

FIGURE 2 is a complete longitudinal section of the same embodiment;

FIGURE 3 is a longitudinal section of a second embodiment some of the parts being shown in elevation; and

FIGURE 4 is a complete longitudinal section of the embodiment of FIGURE 3.

In the drawings, like reference characters indicate like elements throughout.

The first embodiment of the invention is illustrated in FIGURES l and 2. The driving handle comprises a central shaft 1 surrounded by a coaxial cylindrical shell made of three :parts, namely, outer shell parts 2 and 3 and center shell part 4. A cross shaft 5' extends through center shaft 1 at the level of the outer shell 2 and carries freely rotatable bevelled pinions 6 meshing with a bevelled crown gear 7 freely rotatable on the central shaft 1 and to the outer surface of which the center shell part 4 is secured by any means desired. The pinions 6 also mesh at diametrically opposed points from crown gear 7 with a second crown gear 8 freely rotatable on shaft 1 and provided with a coaxial cylindrical extension 9 having a rounded outer end face I10 provided with an axially directed square hole 11 for receiving the square end of the stern of a screw driver, socket Wrench or the like, which is secured to the driving handle within hole 11 by set screw 12.

The cylindrical extension 9 has at the periphery thereof 3,988,338 Patented May 7, 1963 a plurality of ratchet holes 13 engageable by a spring pressed pawl 14 extending within a radial bore made in a bushing 15 surrounding cylindrical extension 9 and secured to the outer shell part 2. Bushing 15 is freely rotatable with respect to cylindrical extension 9 :but is prevented from longitudinal movement with respect to the same :by means of a pin 16 extending through bushing 15 and slidably engaging a peripheral groove 17 of cylindrical extension 9. The shaft 1 is provided near its outer end With a groove 18 engaged by a locking pin 19 inserted within a hole made in the inner cylindrical face of extension 9, thus the shaft is freely rotatable with respect to crown gear 8 and its cylindrical extension 9, but is prevented from longitudinal displacement with respect to the same. Thus, the pinions 6 are positively maintained in meshing engagement with crown gear 8.

A cylindrical bushing 20 freely surrounds the other end of central shaft '1, but is prevented from longitudinal displacement with respect to the same by means of a pin 21 passing through bushing 20 and slidably engaging a groove 22 made in shaft 1. The outer shell part 3 is secured to the outer face of 'bushing 20 and abuts central shell part 4, such that the three shell parts 2, 3 and 4 are maintained in edge to edge abutment and that crown gear 7 is positively maintained in meshing engagement with pinions 6.

The outer end of shaft '1 adjacent groove 22 is provided with peripheral ratchet holes 23 engageable with a spring pressed pawl 24 radially extending through hushing 20. The outer end of shaft 1 adjacent its groove 22 is provided with a square hole 25 for removably receiving the square end of the stem of the screw driver, socket wrench or the like, which is maintained in position by means of a set screw (not shown) similar to set screw 12 at the opposite end of the driving handle. The pawls 14 and 24 are of the type which are reversible.

In the use of the device, when the stem of a nail driver, socket wrench or the like, is fitted within hole 25, and that pawl 14 locks bushing 15 to cylindrical extension 9 of crown gear 8, while pawl 14 allows free rotation of the shaft 1 with respect to bushing 20 in the same direction of rotation, it will be understood that, by grasping the center shell part 4 and also if desired, the shell part 3 and holding them stationary while effecting rotation of the outer shell part 2, crown gear 8 will rotate the pinions 6 against the reaction member constituted by stationary crown gear 7. The pinions 8 will rotate shaft 1 through cross shaft 5 and consequently the tool stem directly secured to shaft 1. During this movement, a demultiplication of the rotational speed will take place, that is the tool will rotate at a lesser speed than the outer shell part 2, thus obtaining a greater torque at the tool itself.

It will be noted that the torque exerted on central shaft 1 is completely balanced on each side of said shaft due to the cross shaft and pinion arrangement which are symmetrically mounted on each side of the shaft. Moreover due to the fact that the teeth of the crown gears are inwardly inclined towards the axis of said gears, the pinions will tend to move radially inwardly on their cross shaft 5 thereby resulting in a minimum of friction in the transmission mechanism.

If the lower pawl 24 is engaged with shaft 1 the same results would be obtained as above, except that only central shell part 4 will be maintained stationary, and will have to be grasped.

If the tool stem is fitted within hole 11 at end face and that both pawls are engaged to prevent rotation of the engaged elements in the same direction and that the shell parts 3 and 4 are grasped, the latter being held stationary, rotation of shell part 3 will result in an increased rotation of crown gear 8, and the tool stem secured thereto. If the pawl 14 is free of engagement with cylindrical extension 9, then the outer shell part 2 as well as central part 4 will be grasped to be maintained stationary, but with the same results, that is an increase in the speed of rotation of the tool with respect to the actuator shell part 3. Thus, the driver handle in accordance with the first embodiment can beusedto obtain a lower or a higher speed ratio.

The second embodiment of the invention illustrated in FIGURES 3 and 4 is based on the same principle as the first embodiment, except that it provides for a still greater difference in the speeds of rotation of the input and output ends of the driving handle. The second embodiment comprises a central shaft 30 coaxially mounted within a cylindrical shell consisting of outer shell parts 31 and 32 and center shell part 33. A first cross shaft 36 and a second cross shaft 37 are inserted across shaft and are rigid therewith, said cross shafts being longitudinally spaced along shaft 30. A pair of double bevelled pinions 38 are freely rotatably mounted on the first cross shaft 36 while a pair of simple bevelled pinions 39 are pivotally mounted on the second cross shaft 37 on each side of central shaft 30. The radially outer set of gear teeth 38' of double bevelled pinions 38 together with the gear teeth of pinions 39 are radially inwardly inclined in a direction away from central shaft 30 to mesh with one set of gear teeth of a double crown gear 40 disposed intermediate pinions 38 and 39 and the sets of gear teeth of which are inwardly inclined towards central shaft 30. Crown gear 40 is freely rotatable on central shaft 30 and is disposed opposite and issecured to center shell part 33. The inner set of gear teeth 38" of the double bevelled pinions 38are radially inwardly inclined towards shaft 30 and are in meshing engagement with the end bevelled gear teeth 41 of a cylindrical body or crown gear 42 which is freely rotatably mounted on shaft 1, the latter entering anaxial bore made in body 42. The latter is provided with a curved end face 43 provided with an axial square hole 44 for receiving the square end of the stem of a tool, such as a screw driver, socket wrench, or the like.

Body 42 is surrounded by annular bushing 45 secured its pin 48. The outer end of the bushing 56 is provided with an axially directed square hole 59 for removably fitting thereinto, the square end of the stem of a tool such as a screw driver, socket wrench, or the like. Means such as set screw 12 in the first embodiment are preferably provided for the two square holes 59 and 44 of the second embodiment.

In the use of the invention, supposing the driven tool is secured within square hole 59 and the two pawls 49 and 55 are in locking engagement with body 42 and crown gear 52 respectively, the driving handle is grasped by central shell part 33 to be maintained stationary and by outer shell part 31 which is rotated with the other hand whereby rotation of body 42 causes rotation of central shaft through the intermediary of double bevelled pinions 38" and first cross shaft 36. The outer set of pinions 38 meshes with the reaction member constituted by the stationary double crown gear 40. The central shaft 30 rotates the second cross shaft 37 and its bevelled pinions 39, which mesh with the reaction member constituted by double crown gear 40, drive crown gear 52 at an increased speed which rotate bushing 56 through the locking of pawl'55 and consequently drive the tool secured to bushing 56 at a smaller speed than the speed of rotation of outer shell part 31. The pawls 47 and 55 allow free return movement of the outer shell 31 while the tool itself remains stationary. The pawls being reversible, it is understood that the tool may be used for driving in any one of the two directions of rotation.

If the tool to be driven is secured to the opposite end of the driving handle, that is fitted within square hole 44, and that the two pawls 47 and 55 remain in locking engagement, the tool to be driven will be rotated at a much greater speed than outer shell part 32, the latter being rotated while central shell part 33 is held stationary. If desired, the pawl 47 can be released in which case both outer shell part 31 and center shell part 33 may be held stationary. As in the first embodiment, the torque transmitted to central shaft is dynamically balanced on each side thereof due to the arrangement of the cross shafts 36 and 37 and their symmetrical pinions. It will be understood that the gear ratios may be varied so as to obtain the desired speed difierence between the input and output ends of the driving handle.

While preferred embodiments in accordance with the a present invention have been illustrated and described, it

within the outer end of outer shell 31 and provided at its periphery with a series of ratchet notches 46 engageable with a spring pressed pawl 47 radially extending through bushing 45. Longitudinal movement of shaft 30 with respect tobody 42 is prevented by pin 48 engaging a hole within the bore of body 42 and slidably engaged with a peripheral groove 49 made in the end of shaft 30. Longitudinal movement of bushing 45 with respect to body 42 is prevented by means of a pin 50 radially inserted within bushing 45 and slidably engaging an annular groove 51 made in the outer surface of body 42.

' Pinions 39 on the second cross shaft 37 are in meshing engagement with a crown gear 52 freely rotatable on central shaft 30 and having its gear teeth inwardly inclined in the direction of shaft 30. Crown gear 52 is provided opposite its gear teeth with a cylindrical boss 53 having ratchet notches 54 engageable by a spring pressed pawl 55 radially mounted within a bore of bushing 56 secured to outer shell part 32 and freely rotatable on central shaft 30. A pin 57 radially inserted within bushing 56 and engaging a groove 58 made in central shaft 30 prevents longitudinal'displacement of the bushing with respect to the shaft and positively maintains the various gears in meshing engagement together with body 42 and is understood that various modifications may be resorted to without departing from the spirit and scope of the appended claims.

What I claim is:

1. A driving handle for rotary tools comprising a cylindrical shell made of at least first and second separate parts of substantially equal diameter and in end to end relationship, a central shaft coaxial with said shell and mounted therein, a cross shaft secured to said central shaft and extending on opposite sides of the latter, pinions freely rotatably mounted on said cross shaft on opposite sides of said central shaft, 21 first crown gear freely rotatably mounted on said central shaft and meshing with said pinions, means connecting said first crown gear with said first shell part, a second crown gear freely rotatably mounted on said central shaft and meshing with said pinions, the teeth of said crown gears being inwardly inclined towards the axis thereof, means connecting said second shell part to said second crown gear whereby rotation of said second shell art relative to said first shell part will cause rotation of said central shaft at a reduced speed, means at the ends of said handle for removably connecting a rotary tool, a third shell part opposite to said second shell part with respect to said first shell part, a bushing fitted within and secured to said third shell part, said bushing freely rotatably mounted on said central shaft, said first crown gear being a double crown gear, a second cross shaft secured to said central shaft and extending on opposite sides of the latter, second pinions freely rotatably mounted on said second cross shaft on opposite sides of said central shaft and meshing with said first double crown gear, a third crown gear freely rotatably mounted on said central shaft and meshing with 5 said second pinions, and pawl and ratchet means between said bushing and said third crown gear.

2. A driving handle as claimed in claim 1, wherein said means for removably connecting a rotary tool include non-circular holes made in said bushing and in said 10 second crown gear, axially of said central shaft.

References Cited in the file of this patent UNITED STATES PATENTS Menzies et a1. Jan. 10, 1911 Nolan June 30, 1925 Stoll Oct. 9, 1934 Johnson Apr. 14, 1953 Ondeck Feb. 12, 1957 FOREIGN PATENTS Germany Sept. 12, 1929 

1. A DRIVING HANDLE FOR ROTARY TOOLS COMPRISING A CYLINDRICAL SHELL MADE OF AT LEAST FIRST AND SECOND SEPARATE PARTS OF SUBSTANTIALLY EQUAL DIAMETER AND IN END TO END RELATIONSHIP, A CENTRAL SHAFT COAXIAL WITH SAID SHELL AND MOUNTED THEREIN, A CROSS SHAFT SECURED TO SAID CENTRAL SHAFT AND EXTENDING ON OPPOSITE SIDES OF THE LATTER, PINIONS FREELY ROTATABLY MOUNTED ON SAID CROSS SHAFT ON OPPOSITE SIDES OF SAID CENTRAL SHAFT, A FIRST CROWN GEAR FREELY ROTATABLY MOUNTED ON SAID CENTRAL SHAFT AND MESHING WITH SAID PINIONS, MEANS CONNECTING SAID FIRST CROWN GEAR WITH SAID FIRST SHELL PART, A SECOND CROWN GEAR FREELY ROTATABLY MOUNTED ON SAID CENTRAL SHAFT AND MESHING WITH SAID PINIONS, THE TEETH OF SAID CROWN GEARS BEING INWARDLY INCLINED TOWARDS THE AXIS THEREOF, MEANS CONNECTING SAID SECOND SHELL PART TO SAID SECOND CROWN GEAR WHEREBY ROTATION OF SAID SECOND SHELL PART RALATIVE TO SAID FIRST SHELL PART WILL CAUSE ROTATION OF SAID CENTRAL SHAFT AT A REDUCED 